William Thorn (3 September 1852 – 1 February 1935) was a grazier and politician in Queensland, Australia. He was a Member of the Queensland Legislative Assembly.
William Thorn was born in September 1852 in Ipswich, Colony of New South Wales, the son of George Thorn and his wife Jane, née Hancock.
William Thorn was elected to the Queensland Legislative Assembly in the electoral district of Aubigny from 1894 to 1904 and again from 1908 to 1912.
The former Wilthorn railway station in Kelvinhaugh on the Cooyar railway line was named after him.
William Thorn died on 1 February 1935 at his son's pastoral property Milford Rocks, Crows Nest, Queensland and was buried in Drayton and Toowoomba Cemetery.